1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * TI Touch Screen / ADC MFD driver 4 * 5 * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com/ 6 */ 7 8 #include <linux/module.h> 9 #include <linux/slab.h> 10 #include <linux/err.h> 11 #include <linux/io.h> 12 #include <linux/clk.h> 13 #include <linux/regmap.h> 14 #include <linux/mfd/core.h> 15 #include <linux/pm_runtime.h> 16 #include <linux/of.h> 17 #include <linux/of_device.h> 18 #include <linux/sched.h> 19 20 #include <linux/mfd/ti_am335x_tscadc.h> 21 22 static const struct regmap_config tscadc_regmap_config = { 23 .name = "ti_tscadc", 24 .reg_bits = 32, 25 .reg_stride = 4, 26 .val_bits = 32, 27 }; 28 29 void am335x_tsc_se_set_cache(struct ti_tscadc_dev *tscadc, u32 val) 30 { 31 unsigned long flags; 32 33 spin_lock_irqsave(&tscadc->reg_lock, flags); 34 tscadc->reg_se_cache |= val; 35 if (tscadc->adc_waiting) 36 wake_up(&tscadc->reg_se_wait); 37 else if (!tscadc->adc_in_use) 38 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 39 40 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 41 } 42 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_cache); 43 44 static void am335x_tscadc_need_adc(struct ti_tscadc_dev *tscadc) 45 { 46 DEFINE_WAIT(wait); 47 u32 reg; 48 49 regmap_read(tscadc->regmap, REG_ADCFSM, ®); 50 if (reg & SEQ_STATUS) { 51 tscadc->adc_waiting = true; 52 prepare_to_wait(&tscadc->reg_se_wait, &wait, 53 TASK_UNINTERRUPTIBLE); 54 spin_unlock_irq(&tscadc->reg_lock); 55 56 schedule(); 57 58 spin_lock_irq(&tscadc->reg_lock); 59 finish_wait(&tscadc->reg_se_wait, &wait); 60 61 /* 62 * Sequencer should either be idle or 63 * busy applying the charge step. 64 */ 65 regmap_read(tscadc->regmap, REG_ADCFSM, ®); 66 WARN_ON((reg & SEQ_STATUS) && !(reg & CHARGE_STEP)); 67 tscadc->adc_waiting = false; 68 } 69 tscadc->adc_in_use = true; 70 } 71 72 void am335x_tsc_se_set_once(struct ti_tscadc_dev *tscadc, u32 val) 73 { 74 spin_lock_irq(&tscadc->reg_lock); 75 am335x_tscadc_need_adc(tscadc); 76 77 regmap_write(tscadc->regmap, REG_SE, val); 78 spin_unlock_irq(&tscadc->reg_lock); 79 } 80 EXPORT_SYMBOL_GPL(am335x_tsc_se_set_once); 81 82 void am335x_tsc_se_adc_done(struct ti_tscadc_dev *tscadc) 83 { 84 unsigned long flags; 85 86 spin_lock_irqsave(&tscadc->reg_lock, flags); 87 tscadc->adc_in_use = false; 88 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 89 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 90 } 91 EXPORT_SYMBOL_GPL(am335x_tsc_se_adc_done); 92 93 void am335x_tsc_se_clr(struct ti_tscadc_dev *tscadc, u32 val) 94 { 95 unsigned long flags; 96 97 spin_lock_irqsave(&tscadc->reg_lock, flags); 98 tscadc->reg_se_cache &= ~val; 99 regmap_write(tscadc->regmap, REG_SE, tscadc->reg_se_cache); 100 spin_unlock_irqrestore(&tscadc->reg_lock, flags); 101 } 102 EXPORT_SYMBOL_GPL(am335x_tsc_se_clr); 103 104 static void tscadc_idle_config(struct ti_tscadc_dev *tscadc) 105 { 106 unsigned int idleconfig; 107 108 idleconfig = STEPCONFIG_INM_ADCREFM | STEPCONFIG_INP_ADCREFM; 109 if (ti_adc_with_touchscreen(tscadc)) 110 idleconfig |= STEPCONFIG_YNN | STEPCONFIG_YPN; 111 112 regmap_write(tscadc->regmap, REG_IDLECONFIG, idleconfig); 113 } 114 115 static int ti_tscadc_probe(struct platform_device *pdev) 116 { 117 struct ti_tscadc_dev *tscadc; 118 struct resource *res; 119 struct clk *clk; 120 struct device_node *node; 121 struct mfd_cell *cell; 122 struct property *prop; 123 const __be32 *cur; 124 bool use_tsc = false, use_mag = false; 125 u32 val; 126 int err; 127 int tscmag_wires = 0, adc_channels = 0, cell_idx = 0, total_channels; 128 int readouts = 0, mag_tracks = 0; 129 130 /* Allocate memory for device */ 131 tscadc = devm_kzalloc(&pdev->dev, sizeof(*tscadc), GFP_KERNEL); 132 if (!tscadc) 133 return -ENOMEM; 134 135 tscadc->dev = &pdev->dev; 136 137 if (!pdev->dev.of_node) { 138 dev_err(&pdev->dev, "Could not find valid DT data.\n"); 139 return -EINVAL; 140 } 141 142 tscadc->data = of_device_get_match_data(&pdev->dev); 143 144 if (ti_adc_with_touchscreen(tscadc)) { 145 node = of_get_child_by_name(pdev->dev.of_node, "tsc"); 146 of_property_read_u32(node, "ti,wires", &tscmag_wires); 147 err = of_property_read_u32(node, "ti,coordinate-readouts", 148 &readouts); 149 if (err < 0) 150 of_property_read_u32(node, "ti,coordiante-readouts", 151 &readouts); 152 153 of_node_put(node); 154 155 if (tscmag_wires) 156 use_tsc = true; 157 } else { 158 /* 159 * When adding support for the magnetic stripe reader, here is 160 * the place to look for the number of tracks used from device 161 * tree. Let's default to 0 for now. 162 */ 163 mag_tracks = 0; 164 tscmag_wires = mag_tracks * 2; 165 if (tscmag_wires) 166 use_mag = true; 167 } 168 169 node = of_get_child_by_name(pdev->dev.of_node, "adc"); 170 of_property_for_each_u32(node, "ti,adc-channels", prop, cur, val) { 171 adc_channels++; 172 if (val > 7) { 173 dev_err(&pdev->dev, " PIN numbers are 0..7 (not %d)\n", 174 val); 175 of_node_put(node); 176 return -EINVAL; 177 } 178 } 179 180 of_node_put(node); 181 182 total_channels = tscmag_wires + adc_channels; 183 if (total_channels > 8) { 184 dev_err(&pdev->dev, "Number of i/p channels more than 8\n"); 185 return -EINVAL; 186 } 187 188 if (total_channels == 0) { 189 dev_err(&pdev->dev, "Need at least one channel.\n"); 190 return -EINVAL; 191 } 192 193 if (use_tsc && (readouts * 2 + 2 + adc_channels > 16)) { 194 dev_err(&pdev->dev, "Too many step configurations requested\n"); 195 return -EINVAL; 196 } 197 198 err = platform_get_irq(pdev, 0); 199 if (err < 0) 200 return err; 201 else 202 tscadc->irq = err; 203 204 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 205 tscadc->tscadc_base = devm_ioremap_resource(&pdev->dev, res); 206 if (IS_ERR(tscadc->tscadc_base)) 207 return PTR_ERR(tscadc->tscadc_base); 208 209 tscadc->tscadc_phys_base = res->start; 210 tscadc->regmap = devm_regmap_init_mmio(&pdev->dev, 211 tscadc->tscadc_base, 212 &tscadc_regmap_config); 213 if (IS_ERR(tscadc->regmap)) { 214 dev_err(&pdev->dev, "regmap init failed\n"); 215 return PTR_ERR(tscadc->regmap); 216 } 217 218 spin_lock_init(&tscadc->reg_lock); 219 init_waitqueue_head(&tscadc->reg_se_wait); 220 221 pm_runtime_enable(&pdev->dev); 222 pm_runtime_get_sync(&pdev->dev); 223 224 /* 225 * The TSC_ADC_Subsystem has 2 clock domains: OCP_CLK and ADC_CLK. 226 * ADCs produce a 12-bit sample every 15 ADC_CLK cycles. 227 * am33xx ADCs expect to capture 200ksps. 228 * am47xx ADCs expect to capture 867ksps. 229 * We need ADC clocks respectively running at 3MHz and 13MHz. 230 * These frequencies are valid since TSC_ADC_SS controller design 231 * assumes the OCP clock is at least 6x faster than the ADC clock. 232 */ 233 clk = devm_clk_get(&pdev->dev, NULL); 234 if (IS_ERR(clk)) { 235 dev_err(&pdev->dev, "failed to get fck\n"); 236 err = PTR_ERR(clk); 237 goto err_disable_clk; 238 } 239 240 tscadc->clk_div = (clk_get_rate(clk) / tscadc->data->target_clk_rate) - 1; 241 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); 242 243 /* 244 * Set the control register bits. tscadc->ctrl stores the configuration 245 * of the CTRL register but not the subsystem enable bit which must be 246 * added manually when timely. 247 */ 248 tscadc->ctrl = CNTRLREG_STEPID; 249 if (ti_adc_with_touchscreen(tscadc)) { 250 tscadc->ctrl |= CNTRLREG_TSC_STEPCONFIGWRT; 251 if (use_tsc) { 252 tscadc->ctrl |= CNTRLREG_TSC_ENB; 253 if (tscmag_wires == 5) 254 tscadc->ctrl |= CNTRLREG_TSC_5WIRE; 255 else 256 tscadc->ctrl |= CNTRLREG_TSC_4WIRE; 257 } 258 } else { 259 tscadc->ctrl |= CNTRLREG_MAG_PREAMP_PWRDOWN | 260 CNTRLREG_MAG_PREAMP_BYPASS; 261 } 262 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl); 263 264 tscadc_idle_config(tscadc); 265 266 /* Enable the TSC module enable bit */ 267 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB); 268 269 /* TSC or MAG Cell */ 270 if (use_tsc || use_mag) { 271 cell = &tscadc->cells[cell_idx++]; 272 cell->name = tscadc->data->secondary_feature_name; 273 cell->of_compatible = tscadc->data->secondary_feature_compatible; 274 cell->platform_data = &tscadc; 275 cell->pdata_size = sizeof(tscadc); 276 } 277 278 /* ADC Cell */ 279 if (adc_channels > 0) { 280 cell = &tscadc->cells[cell_idx++]; 281 cell->name = tscadc->data->adc_feature_name; 282 cell->of_compatible = tscadc->data->adc_feature_compatible; 283 cell->platform_data = &tscadc; 284 cell->pdata_size = sizeof(tscadc); 285 } 286 287 err = mfd_add_devices(&pdev->dev, PLATFORM_DEVID_AUTO, 288 tscadc->cells, cell_idx, NULL, 0, NULL); 289 if (err < 0) 290 goto err_disable_clk; 291 292 platform_set_drvdata(pdev, tscadc); 293 return 0; 294 295 err_disable_clk: 296 pm_runtime_put_sync(&pdev->dev); 297 pm_runtime_disable(&pdev->dev); 298 299 return err; 300 } 301 302 static int ti_tscadc_remove(struct platform_device *pdev) 303 { 304 struct ti_tscadc_dev *tscadc = platform_get_drvdata(pdev); 305 306 regmap_write(tscadc->regmap, REG_SE, 0x00); 307 308 pm_runtime_put_sync(&pdev->dev); 309 pm_runtime_disable(&pdev->dev); 310 311 mfd_remove_devices(tscadc->dev); 312 313 return 0; 314 } 315 316 static int __maybe_unused ti_tscadc_can_wakeup(struct device *dev, void *data) 317 { 318 return device_may_wakeup(dev); 319 } 320 321 static int __maybe_unused tscadc_suspend(struct device *dev) 322 { 323 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev); 324 325 regmap_write(tscadc->regmap, REG_SE, 0x00); 326 if (device_for_each_child(dev, NULL, ti_tscadc_can_wakeup)) { 327 u32 ctrl; 328 329 regmap_read(tscadc->regmap, REG_CTRL, &ctrl); 330 ctrl &= ~(CNTRLREG_POWERDOWN); 331 ctrl |= CNTRLREG_SSENB; 332 regmap_write(tscadc->regmap, REG_CTRL, ctrl); 333 } 334 pm_runtime_put_sync(dev); 335 336 return 0; 337 } 338 339 static int __maybe_unused tscadc_resume(struct device *dev) 340 { 341 struct ti_tscadc_dev *tscadc = dev_get_drvdata(dev); 342 343 pm_runtime_get_sync(dev); 344 345 regmap_write(tscadc->regmap, REG_CLKDIV, tscadc->clk_div); 346 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl); 347 tscadc_idle_config(tscadc); 348 regmap_write(tscadc->regmap, REG_CTRL, tscadc->ctrl | CNTRLREG_SSENB); 349 350 return 0; 351 } 352 353 static SIMPLE_DEV_PM_OPS(tscadc_pm_ops, tscadc_suspend, tscadc_resume); 354 355 static const struct ti_tscadc_data tscdata = { 356 .adc_feature_name = "TI-am335x-adc", 357 .adc_feature_compatible = "ti,am3359-adc", 358 .secondary_feature_name = "TI-am335x-tsc", 359 .secondary_feature_compatible = "ti,am3359-tsc", 360 .target_clk_rate = TSC_ADC_CLK, 361 }; 362 363 static const struct ti_tscadc_data magdata = { 364 .adc_feature_name = "TI-am43xx-adc", 365 .adc_feature_compatible = "ti,am4372-adc", 366 .secondary_feature_name = "TI-am43xx-mag", 367 .secondary_feature_compatible = "ti,am4372-mag", 368 .target_clk_rate = MAG_ADC_CLK, 369 }; 370 371 static const struct of_device_id ti_tscadc_dt_ids[] = { 372 { .compatible = "ti,am3359-tscadc", .data = &tscdata }, 373 { .compatible = "ti,am4372-magadc", .data = &magdata }, 374 { } 375 }; 376 MODULE_DEVICE_TABLE(of, ti_tscadc_dt_ids); 377 378 static struct platform_driver ti_tscadc_driver = { 379 .driver = { 380 .name = "ti_am3359-tscadc", 381 .pm = &tscadc_pm_ops, 382 .of_match_table = ti_tscadc_dt_ids, 383 }, 384 .probe = ti_tscadc_probe, 385 .remove = ti_tscadc_remove, 386 387 }; 388 389 module_platform_driver(ti_tscadc_driver); 390 391 MODULE_DESCRIPTION("TI touchscreen/magnetic stripe reader/ADC MFD controller driver"); 392 MODULE_AUTHOR("Rachna Patil <rachna@ti.com>"); 393 MODULE_LICENSE("GPL"); 394